Waste‐Derived Copper‐Lead Electrocatalysts for CO₂ Reduction

Abstract

It remains a real challenge to control the selectivity of the electrocatalytic CO 2 reduction (eCO 2 R) reaction to valuable chemicals and fuels. Most of the electrocatalysts are made of non-renewable metal resources, which hampers their largescale implementation. Here, we report the preparation of bimetallic copper-lead (CuPb) electrocatalysts from industrial metallurgical waste. The metal ions were extracted from the metallurgical waste through simple chemical treatment with ammonium chloride, and Cu x Pb y electrocatalysts with tunable compositions were fabricated through electrodeposition at varying cathodic potentials. X-ray spectroscopy techniques showed that the pristine electrocatalysts consist of Cu 0 , Cu 1 + and Pb 2 + domains, and no evidence for alloy formation was found. We found a volcano-shape relationship between eCO 2 R selectivity toward two electron products, such as CO, and the elemental ratio of Cu and Pb. A maximum Faradaic efficiency towards CO was found for Cu 9.00 Pb 1.00 , which was four times higher than that of pure Cu, under the same electrocatalytic conditions. In situ Raman spectroscopy revealed that the optimal amount of Pb effectively improved the reducibility of the pristine Cu 1 + and Pb 2 + domains to metallic Cu and Pb, which boosted the selectivity towards CO by synergistic effects. This work provides a framework of thinking to design and tune the selectivity of bimetallic electrocatalysts for CO 2 reduction through valorization of metallurgical waste.

Waste to wealth: direct utilization of spent materials for electrocatalysis and energy storage

“…By using industrial metallurgical wastes as raw materials, Yang et al extracted Cu and lead (Pb) from industrial wastewater by electrodeposition, preparing a series of copper-lead (Cu x Pb y ) materials as CO 2 RR catalysts. 33 It is found that there is a synergistic effect between Cu and Pb in the prepared bimetallic electrocatalysts, especially, the Cu + and Pb 2+ species that can be reduced to Cu 0 and Pb 0 metal. The reduced species play an important role in the formation of CO, which promotes the enhancement of CO selectivity (the amount of CO formed at −1.05 V vs. RHE is about 4 times that of pure Cu).…”

“…29,30 Even industrial waste materials such as copper in waste wire, steel wire in waste tires, silicon in waste photovoltaic materials, various metals in waste circuit boards, and valuable metals and elements in solid or liquid wastes contribute to a large market prospect for reutilization. 25,[31][32][33] To date, a few reviews have been published on the utilization of biomass derived electrocatalysts in energy storage that focus on the synthetic strategies and functionalization. 7,34,35 A review was recently published on the design of electrocatalysts from waste and natural materials.…”

“…29,30 Even industrial waste materials such as copper in waste wire, steel wire in waste tires, silicon in waste photovoltaic materials, various metals in waste circuit boards, and valuable metals and elements in solid or liquid wastes contribute to a large market prospect for reutilization. 25,31–33…”

The Necessity for Multiscale In Situ Characterization of Tailored Electrocatalyst Nanoparticle Stability

“…Furthermore, the rise of synthesis strategies for nanoparticles with well-defined surfaces (i.e., anisotropic growth of nanowires or nanoplatelets) , and compositions (e.g., bimetallic, alloys, heteronanostructures) ,,, has further expanded the library of products that can be obtained through CO 2 reduction at high conversion rate. As a result, many tunable (bi)­metallic electrocatalysts have emerged as a viable strategy to tailor the electrocatalytic CO 2 reduction reaction (eCO 2 RR) for the selective production of valuable base chemicals and fuels. ,, For example, Cu–Ag dimers and heterostructures have been synthesized, which displayed CO 2 to CO conversion on Ag sites, and CO spillover and concomitant CO–CO coupling on Cu, resulting in boosted ethylene production compared to the monometallic counterparts. , Furthermore, it has been shown that combinations of Cu with post-transition metals (e.g., Sn) results in near unity CO production, whereas neither Cu nor Sn is very selective for CO on its own . Interestingly, bimetallic configurations are inferred to come with an additional benefit: doping of a secondary metal induces NP stabilization due to nanoscale strain effects .…”

Repurposing metal containing wastes and mass-produced materials as electrocatalysts for water electrolysis

“…The selectivity towards CO formation was improved when the alloys were galvanically replaced with Ag. Yang et al 164 showed that bimetallic copper−lead (CuPb) electrocatalysts could be prepared from industrial metallurgical waste with the composition of Cu 9 Pb 1 , which exhibited a faradaic efficiency for CO formation that was four times higher than that of pure Cu. Indeed, using metal residues produced in the metallurgical industry to prepare electrocatalysts for CO 2 conversion is gaining more attention.…”